Merge Multiple Files in Java: Explanation & Practice

Problem summary

Merge the contents of multiple text files into one output file.

Starter code

import java.io.*;

public class Main {
    public static void main(String[] args) {
        String[] files = {"file1.txt", "file2.txt", "file3.txt"};
        
        // Merge all files into merged.txt
        // Print: Merged <count> files
    }
}

Expected output and test cases

• Three files merged

  Merged 3 files

• Single file

  Merged 1 files

• Five files

  Merged 5 files

Hints

1. Open output file once
2. Loop through input files
3. Append each file's content

Related File I/O exercises

• Practice Search in File in Java
• Practice Reverse File Lines in Java
• Practice Remove Duplicate Lines in Java

Practice all File I/O exercises · Run this idea in the Java compiler